Assistive Technology: Vision Products

Original Editor - Robin Tacchetti Top Contributors - Robin Tacchetti, Naomi O'Reilly and Kim Jackson

Introduction

Globally, millions of people have vision loss or a visual impairment. Recent estimates that there are over 43 million blind people and 295 million people suffering from moderate-to-severe visual impairment with the majority of these individuals living in middle and low-income countries. Visual impairment can be classified by one's visual acuity:

• blind: vision below 20/400
• low vision: corrected vision is less than 20/70 and greater than or equal to 20/400

Visual impairment impacts quality of life in various ways such functional daily activities, indoor and outdoor movement, employment and independence. Additionally, dangerous situations can occur when these individuals encounter environments unfamiliar to them. These barriers individuals face daily can be overcome with the help of assistive technology. The wide range of vision assistive technology can be a simple low-tech device (large print book) to an expensive high-tech solution such as a Refreshable Braille Display. Recent advances in technology have expanded the digital assistive technology space.

Global Cooperation on Assistive Technology (GATE)

In 2014, the World Health Organization introduced the Global Cooperation on Assistive Technology (GATE). This initiative's addresses the significant gap in all countries between supply and demand for assistive technology. GATE published a list of the top 50 priority assistive products based on widespread need amongst the disabled population. Of those 50 priority products, 16 are geared towards people with visual impairments. These vision assistive products help by the use of sound, smell, or sense of touch or vibration.

Different Types of AT (borges)

1. Optical:
   • prescribed by ophthalmologists
   • consist of one or more lenses to adjust/increase visual image
   • devices can include: eyeglasses, telescopes, contact lenses, magnifying glasses
2. Non-optical
   • improve vision without use of lenses
   • simple, transform environment and materials
   • devices include: enlarged text, lighting, felt tip pens, contrasting colors, didactic books
3. Electronic
   • provide access to printed material that optical magnifying glasses are not able to expand enough for reading
   • able to magnify up to 66 times without distorion
   • devices include: scanners, autonomous text readers, video magnifiers, electronic magnifying glass
4. Information and Communication Technology (ICT)
   • works through a combination of sound, tactile and visual interfaces
   • devices include: computer, screen magnifier software, screen readers

Reading

Many activities in our daily lives requires the act of reading. These assistive devices below can help individuals with visual impairment:

1. large print books
2. reading stands
3. low vision lamps
4. optimal magnifiers
5. electronic magnification aids
6. braille reading systems
7. screen readers
8. digital audio recorders

Math

It can be very challenging for children with visual impairment to learn math concepts. It can be very difficult to interpret shapes, direction and quantification without visual input. The following devices can help support them:

1. Braille systems
2. talking calculator
3. tactile geometric kit

Writing

Typical or visual writing can be particularly challenging for individuals with visual impairment. The following devices can assist them:

1. braille systems
2. large computer keyboards
3. audio digital recorder

Orientation and Mobility

Walking is a necessary element of daily life. Below is a list of a variety of canes that can assist individuals with visual impairment.

1. walking: identifies objects in the path of the user
2. identification: notifies general public that the user has a visual impairment
3. guide: identifies curbs and steps for users with some residual visual function
4. support: provides physical support for the user
5. green: indicates user has low vision
6. white: indicates user is blind

ADL

Assistive technology can help individuals perform ADLs to allow more independence in their daily routine. Below are some devices that can be incorporated into a visually impaired person's life:

1. talking watch
2. pill organizer
3. simplified mobile phone: easier to navigate
4. money identifier: identifies money with a voice function
5. color identifier: differentiates a variety of colors
6. liquid level sensor: alerts the user about the level of liquid in a cup via sound or vibration

Smart Phone

Many smart digital assistive technologies based on electronic information, communication technology for visual impairment have been gaining a lot of importance across the world in recent times [7, 8]. Such smart assistive technologies have many accessible features and accessible applications for persons with disabilitie. With ongoing advance in smartphone technologies, it is becoming even more feasible for the person with visual impairment to rely on mobile technology in understanding their immediate surrounding, and to access huge amounts information that can improve their level of independent functioning, movement, social inclusion, participation, educational activities, and finally helps in improving the quality of life. large number of accessible built-in features have been developed specifically for people with blindness and visual impairment. ost widely used built-in accessible feature as screen readers are TalkBack for Android (Figure 4) and VoiceOver for Apple iOS (Figure 5) among people with visual impairment [17]. The Talback feature allows the user to easily identify the content or applications icons on the smartphones’ screen with a verbally speak words or voice from the device upon touching with fingers on the icons. By simply placing a finger on the icons, the smartphone will read aloud what icon is underneath the finger. Similarly, VoiceOver provides voice feedback aloud what appear on the smartphones’ screen, so iOS operating smartphone can be used without the need of visual function. A visually disabled individual can slide around on the screen with finger until the desired icons is located.

or a person with a low vision, the zoom magnification feature helps to magnify the entire screen to the required level of individual’s choice. Invert colors allows to change the white text on a black background, and vice versa or blue text on a yellow backgr (SENJAM SMARTPHONE ARTRICLE)- can use table feature insread

References 

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